1. Field of the Invention
The present invention relates generally to the field of telecommunications and, more specifically, to a converged services platform based on a hybrid switching architecture.
2. Background Information
Traditional circuit-switched telecommunications networks, including the public switched telephone network (PSTN), typically include switches in which call control signaling is fully integrated with media switching. Call processing functionality must be tightly coupled, and usually co-located, with media switching hardware in order to implement the traditional switching model. Thus, a switch which operates in accordance with the traditional model consists of a single “box” containing a call processing element (e.g., a CPU running appropriate software), a switching element (e.g., a timeslot inter-changer), one or more line cards capable of supporting desired protocols (e.g., DS3, T1, E1, J1, analog, etc.) or other interfaces (e.g., SS7, IP, etc.) and, in most instances, a capability for performing tone generation/detection, voice recorded announcements, conferencing or similar “media services” as may be required by a given application.
A major disadvantage of the traditional switching model is that, due to the tight coupling between call processing and media switching hardware, it is not particularly flexible and is not well suited to rapid development and deployment of new telecommunications services. In addition, use of the traditional switching model often requires higher capital investment to provide a given service due to the duplication of hardware at multiple locations in a large system.
In the past several years, a growing emphasis on the use of packet-switched networks to provide telecommunications services has given rise to an alternative switching model known as “soft-switching.” Broadly speaking, the soft-switching model is based on a decoupling of call processing from media switching. Such decoupling provides greater flexibility for development and deployment of new services and enables construction of systems in which call processing functionality may be geographically remote from media switching hardware. Such geographical distribution is naturally compatible with packet-switched networks and provides numerous advantages, including elimination of duplicate hardware which would normally be required by use of the traditional switching model.
However, the soft-switching model exhibits disadvantageous characteristics in certain applications. For example, latencies in controlling media switching entities over packet-switched networks may be sufficiently large as to cause noticeable delays in playing tones or announcements to a subscriber, which may in turn cause the subscriber to discontinue use of service. Such an outcome is commercially unacceptable and cannot be tolerated by carriers or other service providers.